So, I consider the "go back in time" aspect of this unnecessarily confusing... the important part from my perspective is what events my timeline contains, not where I am on that timeline.

Indeed, that is my mistake. I am not always the best at choosing metaphors or expressing myself cleanly.

regretting an improperly made decision whose consequences were undesirable, vs. regretting a properly made decision whose consequences were undesirable

That is a very nice way of expressing what I meant. I will be using this from now on to explain what I mean. Thank you.

Your comment helped me to understand what I myself meant much better than before. Thank you for that.